﻿/* Copyright 2010-present MongoDB Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/

using System.Collections;
using System.Collections.Generic;
using System.Linq;
using MongoDB.Driver.Core.Misc;

namespace MongoDB.Driver.Linq.Linq3Implementation.Misc
{
    internal class Grouping<TKey, TElement> : IGrouping<TKey, TElement>
    {
        // private fields
        private readonly TKey _key;
        private readonly List<TElement> _elements;

        // constructors
        public Grouping(TKey key, List<TElement> elements)
        {
            _key = key;
            _elements = Ensure.IsNotNull(elements, nameof(elements));
        }

        // public properties
        public TKey Key => _key;

        // public methods
        public IEnumerator<TElement> GetEnumerator()
        {
            return _elements.GetEnumerator();
        }

        IEnumerator IEnumerable.GetEnumerator()
        {
            return GetEnumerator();
        }
    }
}
